/*
 * brin_internal.h
 *        internal declarations for BRIN indexes
 *
 * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * IDENTIFICATION
 *        src/include/access/brin_internal.h
 */
#ifndef BRIN_INTERNAL_H
#define BRIN_INTERNAL_H

#include "access/amapi.h"
#include "storage/bufpage.h"
#include "utils/typcache.h"


/*
 * A BrinDesc is a struct designed to enable decoding a BRIN tuple from the
 * on-disk format to an in-memory tuple and vice-versa.
 */

/* struct returned by "OpcInfo" amproc */
typedef struct BrinOpcInfo
{
    /* Number of columns stored in an index column of this opclass */
    uint16        oi_nstored;

    /* Opaque pointer for the opclass' private use */
    void       *oi_opaque;

    /* Type cache entries of the stored columns */
    TypeCacheEntry *oi_typcache[FLEXIBLE_ARRAY_MEMBER];
} BrinOpcInfo;

/* the size of a BrinOpcInfo for the given number of columns */
#define SizeofBrinOpcInfo(ncols) \
    (offsetof(BrinOpcInfo, oi_typcache) + sizeof(TypeCacheEntry *) * ncols)

typedef struct BrinDesc
{
    /* Containing memory context */
    MemoryContext bd_context;

    /* the index relation itself */
    Relation    bd_index;

    /* tuple descriptor of the index relation */
    TupleDesc    bd_tupdesc;

    /* cached copy for on-disk tuples; generated at first use */
    TupleDesc    bd_disktdesc;

    /* total number of Datum entries that are stored on-disk for all columns */
    int            bd_totalstored;

    /* per-column info; bd_tupdesc->natts entries long */
    BrinOpcInfo *bd_info[FLEXIBLE_ARRAY_MEMBER];
} BrinDesc;

/*
 * Globally-known function support numbers for BRIN indexes.  Individual
 * opclasses can define more function support numbers, which must fall into
 * BRIN_FIRST_OPTIONAL_PROCNUM .. BRIN_LAST_OPTIONAL_PROCNUM.
 */
#define BRIN_PROCNUM_OPCINFO        1
#define BRIN_PROCNUM_ADDVALUE        2
#define BRIN_PROCNUM_CONSISTENT        3
#define BRIN_PROCNUM_UNION            4
#define BRIN_MANDATORY_NPROCS        4
/* procedure numbers up to 10 are reserved for BRIN future expansion */
#define BRIN_FIRST_OPTIONAL_PROCNUM 11
#define BRIN_LAST_OPTIONAL_PROCNUM    15

#undef BRIN_DEBUG

#ifdef BRIN_DEBUG
#define BRIN_elog(args)            elog args
#else
#define BRIN_elog(args)            ((void) 0)
#endif

/* brin.c */
extern BrinDesc *brin_build_desc(Relation rel);
extern void brin_free_desc(BrinDesc *bdesc);
extern IndexBuildResult *brinbuild(Relation heap, Relation index,
          struct IndexInfo *indexInfo);
extern void brinbuildempty(Relation index);
extern bool brininsert(Relation idxRel, Datum *values, bool *nulls,
           ItemPointer heaptid, Relation heapRel,
           IndexUniqueCheck checkUnique,
           struct IndexInfo *indexInfo);
extern IndexScanDesc brinbeginscan(Relation r, int nkeys, int norderbys);
extern int64 bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm);
extern void brinrescan(IndexScanDesc scan, ScanKey scankey, int nscankeys,
           ScanKey orderbys, int norderbys);
extern void brinendscan(IndexScanDesc scan);
extern IndexBulkDeleteResult *brinbulkdelete(IndexVacuumInfo *info,
               IndexBulkDeleteResult *stats,
               IndexBulkDeleteCallback callback,
               void *callback_state);
extern IndexBulkDeleteResult *brinvacuumcleanup(IndexVacuumInfo *info,
                  IndexBulkDeleteResult *stats);
extern bytea *brinoptions(Datum reloptions, bool validate);

/* brin_validate.c */
extern bool brinvalidate(Oid opclassoid);

#endif                            /* BRIN_INTERNAL_H */
